I bought two white 42 inch ceiling fans off Craigslist. One was $10 and the other was free. These fans work really well in keeping the air from becoming stratified, warm air up and colder air down.
They are older black hunter "original" cast iron fans -- the older ones had greater angle to the blades. They will move a lot of air on high .. but on low they just keep thing moving around. They also run forever w/ oil bath bearing.